Generally, when voltage or current is switched at high speed in an electronic device, unwanted electromagnetic wave is generated, sometimes causing radio or wireless communications interference. Thus, electromagnetic compatibility (EMC) standards have been established by institutions, such as the FCC in the U.S. and the VCCI in Japan, so as to regulate the intensity of an electromagnetic field emitted from electronic devices.
For electronic components mounted on automobiles and trains, independent regulations have been specified by automobile manufacturers and railroad operators. Thus, electronic component manufacturers need to develop and supply electronic components that conform to the regulations.
While various companies' EMC standards for onboard electronic components have provisions regarding EMC testing methodology assuming specific states of implementation, the testing methodology as it stands now does not completely reproduce the actual state of mounting on a vehicle. This is due to the fact that, while the amount of electromagnetic noise radiating from a system varies depending on the implementation conditions of a component or the load, it is difficult to perform the EMC test on an electronic component in every condition in which the component may actually be used.
In this respect, as examples of the noise analysis design technology for electric devices, Patent Documents 1 and 2 may be cited.
Patent Document 1 describes a technology such that, in an electromagnetic field analysis device for significantly decreasing the amount of memory used by a computer and the simulation calculation time, an error between the result of electromagnetic field calculation by simulation and the result of actual electromagnetic field calculation can be minimized.
Patent Document 2 describes a design technique such that, in designing a printed wiring board, an accurate electromagnetic radiation simulation is performed by electromagnetic field analysis.